273 research outputs found

    Immunotoxicity of Zinc Oxide (ZnO) Nanoparticles (NPs) in vitro and in vivo

    Get PDF
    Dept. of Medicine/ì„ì‚ŹWhile Zinc Oxide (ZnO) nanoparticle (NP) has been recognized to have promising applications in biomedicine, its immunotoxicity has been inconsistent and even contradictory. To address this issue, we investigated whether ZnO NPs with different sizes (20 nm or 100 nm) and electrostatic charges (negative or positive) would cause immunotoxicity in vitro and in vivo, and explored their underlying molecular mechanism. Using Raw 264.7 cell line, we examined cell viability, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), and antioxidant enzyme activity to explore the immunotoxicity mechanism of ZnO NPs in vitro. We found that in cell viability assay (CCK-8, real-time xCelligence) ZnO NPs with different size and charge could induce differential cytotoxicity to Raw 264.7 cells. Specifically, the positively charged ZnO NPs exerted higher cytotoxicity than the negatively charged one. Molecular study to unravel the mechanism of immune cell toxicity showed that overall, treatment of ZnO NPs decreased MMP, generated intracellular ROS, and reduced antioxidant enzyme activity such as glutathione peroxidase (GPx). Next, to gauge systemic immunotoxicity, we assessed immune responses of C57BL/6 mice after orally administration of sub-lethal dose of ZnO NPs for two weeks. Oral intake of ZnO NPs significantly decreased body weight gain. In parallel, ZnO NPs did not alter the cell-mediated immune response in mice but suppressed innate immunity such as NK cell activity. The CD4+/CD8+ ratio was slightly reduced which implies the alteration of immune status induced by ZnO NPs. Accordingly, nitric oxide (NO) production from splenocyte culture supernatant in ZnO NP-fed mice was lower than control. Consistently, serum levels of pro/anti-inflammatory (IL-1, TNF-α, and IL-10) and Th1 cytokines (IFN-Îł, IL-12) in ZnO NP-fed mice were significantly suppressed. Collectively, our results indicate that different sized- and charged-ZnO NPs would cause in vitro and in vivo immunotoxicity, of which nature is a minor immunosuppression. This has important implications for individuals who may be chronically exposed to ZnO NPs.ope

    Nitrification of Groundwater Contaminated with NH₄âș Using a Novel Acryl-Resin Fiber for Biomass Attachment

    Full text link
    Joint Research on Environmental Science and Technology for the Eart

    The Visible Light Activity of the TiO2 and TiO2:V4+ Photocatalyst

    Get PDF
    TiO2 and vanadium‐doped TiO2 nanoparticles were synthesized by using the hydrothermal method. The V doping contents are 0.0; 0.1; 0.3; 0.5; 0.7 and 0.9% molar. The vanadium‐doped TiO2 nanoparticles have identical anatase phase with an average crystal size of 10‐20nm. The oleic acid and ethanol solvents with different molar concentrations can make spherical nanograins, or stick form grains, which influence the photo activity of the materials. The absorption spectra of doped samples exhibited long-tailed absorption in the visible light region above 380nm. The visible light photocatalytic activity was evaluated by the degradation of phenol aqueous solutions; after 360 min. under the visible irradiation, the normalized concentration of phenol decreased to 9%

    Preschool STEM Activities and Associated Outcomes: A Scoping Review

    Get PDF
    This review highlights the need for further investigation into the benefits of STEM activities in preschool children’s learning, girls’ engagement and learning of children with disabilities in the STEM field. The review process involved accessing 19 relevant studies from Scopus, ERIC and Google Scholar databases in March 2023. Through the synthesis of information from these studies, seven STEM activities were identified as effective in enhancing preschool children’s learning: educational robots, educational games, argumentative interactions, inquiry-based learning and engineering design, drawing and telling about engineers, free play and pretend play, and group membership. Each of these activities contributes to different learning outcomes for children. Moreover, the review emphasizes the importance of role-playing activities ‘as if’ engineers and scientists, facilitated by teachers, in fostering girls’ motivation and engagement in the STEM field from an early age. Long-term scientific interventions at home have a significant positive impact on the science literacy skills of deaf children. The implications of this review are particularly relevant for early childhood educators, as it provides valuable insights into the use of STEM activities to enhance children’s learning outcomes

    Level of Factors Effects on Customers’ Satisfaction of State Health Insurance in Developing Countries: The Case of Vietnam

    Get PDF
    The article aims to assess the level of factors effecting on customer’s satisfaction with The State Health Insurance, study the case of Vietnam. Parasuraman's SERVQUAL model is utilized to measure the influence of five factors on the customers’ satisfaction with the Vietnam’s State Health Insurance. Five factors are (1) Tangibles, (2) Reliability, (3) Empathy, (4) Assurance and (5) Responsiveness. The data is surveyed by questionnaire by sampling selection method from three Vietnamese largest cities with a total of 764 respondents. Based on the results of Exploratory Factor Analysis (EFA) and multiple regression analysis, five factors have positive effects on the customers’ satisfaction. The level of responsiveness effect is highest, whereas the level of empathy effect is lowest. This empirical result demonstrates that the service quality is essential to create high customers’ satisfaction with The State Health Insurance although it is compulsory for all Vietnamese citizens. Improving service quality is the key to maintain a high covered rate of state health insurance, which contributes to ensuring social security. Keywords: customer’s satisfaction, The State Health Insurance. DOI: 10.7176/JESD/10-24-08 Publication date: December 31st 201

    Complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus) of Vietnam

    Get PDF
    The complete mitochondrial genome of Dong Tao chicken breed (Gallus gallus domesticus, Dong Tao) was obtained by PCR and sequencing. The complete mitogenome was 16,783 bp in length, with the nucleotide composition for A, T, C, G was 30.29%, 23.75%, 32.48%, and 13.48%, respectively. The mitogenome of Dong Tao chicken contained a non-coding control region (D-loop), 2 rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis revealed that breed Dong Tao chicken breed was sister-close to G. gallus breed Guangxi, and paraphyletic to G. spadiceus, S. jabouillei, and a range of Chinese indigenous, ie. breeds Rugao and Taoyuan

    Post-mortem Reproduction from a Vietnamese Perspective—an Analysis and Commentary

    Get PDF
    Post-mortem reproduction is a complex and contested matter attracting attention from a diverse group of scholars and resulting in various responses from a range of countries. Vietnam has been reluctant to deal directly with this matter and has, accordingly, permitted post-mortem reproduction implicitly. First, by analysing Vietnam’s post-mortem reproduction cases, this paper reflects on the manner in which Vietnamese authorities have handled each case in the context of the contemporary legal framework, and it reveals the moral questions arising therefrom. The article then offers an account of Vietnamese social norms as an explanation for the tendency to conduct post-mortem reproduction. In arguing that a deeper and more thorough examination of the moral and ethical reasoning is required, the paper advocates in favour of supportive post-mortem reproduction regulation. In doing so, the paper seeks to reconcile the Vietnamese legal framework and post-mortem reproduction experiences of other countries. The article concludes that Vietnam and countries sharing the similar cultural traits should permit post-mortem reproduction explicitly. This would require full engagement with the ethical and legal issues arising, and careful promulgation of regulations and guidelines based on comparative experiences of a range of countries in handling this matter

    STUDENTS’ OPINIONS ON VOCATIONAL GUIDANCE: A CASE STUDY

    Get PDF
    The problem of employment is always a crucial problem and is the concern of most parents and school students. The survey on the perception of 40 students about vocational guidance was carried out in Nguyen Viet Dung High School in Can Tho City, Vietnam. Results show that students are very concerned about their future career; students have a proper perception of vocational guidance and recognize well factors which affect their career choice.  Article visualizations

    A Giant Frontal Meningioma with Psychiatric Symptoms in a Young Woman: A Case Report

    Get PDF
    Background:Frontal meningioma is often asymptomatic but patients might experience psychiatric symptoms. Since symptoms are atypical in giant meningioma, to the best of our knowledge, we present a rare clinical scenario. Case Presentation: A 24-year old female patient with no medical history presented with two months of depressive symptoms, personality changes such as easy irritability, and feelings of frustration and mental depression, as well as forgetfulness and blurred vision. Brain magnetic resonance imaging (MRI) revealed a well-defined markedly enhancing lesion in the left frontal region measuring 65 x 70 x 70 mm with mass effects to the adjacent brain tissue and associated surrounding edema which was pressed to the frontal horn of the lateral ventricle. The patient underwent frontal unilateral craniotomy and excision of the tumor. After surgery, the quality of life was improved. Conclusion: Meningioma with psychiatric symptoms is quite rare. This clinical case helps clinicians avoid missing symptoms and use appropriate management strategies for patients with giant meningiomas
    • 

    corecore